Systems and methods for crude oil desalting and dehydration in a single vessel

ABSTRACT

A system for crude oil desalting and dehydration in a single vessel is disclosed. The system comprises a pressure vessel defining a cavity and comprising a sealed bulkhead separating the cavity into a first compartment and a second compartment. Disposed within the first compartment is a first distributor disposed within the first compartment, a first electrical grid assembly, and a transfer conduit that passes through the bulkhead from the first compartment to the second compartment, the second compartment being in fluid communication with the first compartment via the transfer conduit. The pressure vessel may further comprise an overflow weir in the first compartment and a second electrical grid assembly disposed within the second compartment and aligned substantially transverse to a flow path extending from the transfer conduit to the crude collection header.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a filing under 35 U.S.C. 371 as the NationalStage of International Application No. PCT/US2017/016737, filed Feb. 6,2017, entitled “SYSTEMS AND METHODS FOR CRUDE OIL DESALTING ANDDEHYDRATION IN A SINGLE VESSEL,” which is incorporated herein byreference in its entirety for all purposes.

BACKGROUND

In some geographical areas, fluid produced from a well may yield crudeoil having substantial quantities of water and undesired substances,such as salt. In some instances, the salt and water content may be sohigh as to interfere with subsequent transportation, storage, andrefining of the crude. Salt and water in the crude may be highlydeleterious to some metal equipment and piping, and therefore it may bedesirable that at least some of the water and undesired substances saltbe separated and removed from the crude.

SUMMARY

In an embodiment, a system for crude oil desalting and dehydration in asingle vessel is disclosed. The system comprises a pressure vesseldefining a cavity and extending along a central axis. The pressurevessel comprises a sealed bulkhead disposed within the cavity, thesealed bulkhead separating the cavity into a first compartment and asecond compartment. The pressure vessel further comprises a firstdistributor disposed within the first compartment, wherein the firstdistributor is configured to receive a crude oil stream and providefluid communication into the first compartment via an inlet of the firstdistributor. The pressure vessel also includes a transfer conduit thatis disposed within the cavity and passes through the bulkhead from thefirst compartment to the second compartment, the second compartmentbeing in fluid communication with the first compartment via the transferconduit. The pressure vessel comprises a first electrical grid assemblydisposed within the first compartment, the first electrical gridassembly disposed between an intake of the transfer conduit and at leasta portion of the first distributor. Also included in the pressure vesselis a crude collector disposed within the second compartment, the crudecollector comprising a collection header configured to communicate thecrude oil out of the second compartment to an outlet of the crudecollector. The pressure vessel further comprises a second electricalgrid assembly disposed within the second compartment and alignedsubstantially transverse to a flow path extending from the transferconduit to the crude collection header.

A method of desalting and dehydrating crude oil via a single pressurevessel is disclosed according to an embodiment. The method comprisesreceiving a crude oil stream into a first distributor disposed within afirst compartment of a pressure vessel, the first compartment beingseparated from a second compartment by a sealed bulkhead, and the firstcompartment comprising a first electrical grid assembly. The methodcontinues by injecting, within the first compartment via the firstdistributor, the crude oil stream before at least a portion of the firstelectrical grid assembly along a first flow path. The method alsoincludes electrostatically coalescing, by passing the diluted crude oilstream through the first electrical grid assembly being energized to afirst voltage potential, water from the crude oil stream into droplets.The method continues with preventing, within the first compartment,coalesced droplets from entering an intake of a transfer conduit byseparating the coalesced droplets from the intake of the transferconduit, wherein the transfer conduit is within the pressure vessel andpasses through the sealed bulkhead and fluidly communicates the crudeoil stream from the first compartment to the second compartment. Themethod also includes transferring the crude oil stream to the secondcompartment via the transfer conduit, and diluting, via a dilutionconduit and a fluid mixer inline with the transfer conduit, the crudeoil stream in the transfer conduit with water. Subsequent to diluting,the method further includes distributing, via a distributor of thetransfer conduit in the second compartment, the diluted crude oil streambefore at least a portion of a second electrical grid assembly. Themethod further comprises electrostatically coalescing, by passing thediluted crude oil stream through the second electrical grid assemblybeing energized to a second voltage potential, water from the dilutedcrude oil stream into droplets. Subsequent to the electrostaticallycoalescing, the method continues with removing crude oil from the secondcompartment via a crude collector disposed within the secondcompartment.

A pressure vessel for crude oil desalting and dehydration is disclosedaccording to another embodiment. The pressure vessel comprises a sealedbulkhead disposed within a cavity defined by the pressure vessel, thesealed bulkhead configured to divide the cavity into a first compartmentand a second compartment. The pressure vessel also includes a firstdistributor disposed within the first compartment, wherein the firstdistributor is configured to receive a crude oil stream and providefluid communication into the first compartment via an inlet of the firstdistributor. The pressure vessel comprises a transfer conduit that isdisposed within the cavity and passes through the bulkhead from thefirst compartment to the second compartment, wherein the transferconduit comprises a collection header configured to receive the crudeoil stream from the first compartment and provide fluid communication tothe second compartment via the transfer conduit. Also included in thepressure vessel is a horizontal electrical grid assembly disposed withinthe first compartment, the horizontal electrical grid assembly disposedbetween the collection header of the transfer conduit and at least aportion of the first distributor. The pressure vessel further includesan overflow weir disposed within the second compartment, wherein theoverflow weir is configured to define a passage over the weir thatdirects the crude oil stream toward a crude outlet and mitigatecoalesced droplets from passing over the overflow weir. Additionally,the pressure vessel comprises a vertical electrical grid assemblydisposed within the second compartment and aligned substantiallytransverse to a horizontal flow path extending from the transfer conduitto the overflow weir, wherein the vertical electrical grid assembly isenergized by a direct current (DC) power transformer.

A pressure vessel for crude oil desalting and dehydration is disclosedaccording to an additional embodiment of the present disclosure. Thepressure vessel comprises a sealed bulkhead disposed within a cavitydefined by the pressure vessel, the sealed bulkhead configured to dividethe cavity into a first compartment and a second compartment. Thepressure vessel further comprises a plurality of distributors disposedwithin the first compartment, wherein each of the plurality ofdistributors is configured to receive a crude oil stream and providefluid communication into the first compartment via inlets. The pressurevessel also includes a transfer conduit that is disposed within thecavity and passes through the bulkhead from the first compartment to thesecond compartment, wherein the transfer conduit comprises a collectionheader configured to receive the crude oil stream from the firstcompartment and provide fluid communication to the second compartmentvia the transfer conduit. The pressure vessel comprises a horizontalelectrical grid assembly disposed within the first compartment, thehorizontal electrical grid assembly disposed between the collectionheader of the transfer conduit and at least one of the plurality ofdistributors. Additionally, the pressure vessel comprises a fluid mixerwithin the pressure vessel and is in fluid communication with thetransfer conduit and disposed between the collection header of thetransfer conduit and a distributor of the transfer conduit disposed inthe second compartment. The pressure vessel further comprises a crudecollector disposed within the second compartment, the crude collectorcomprising a collection header configured to communicate fluid out ofthe second compartment to an outlet of the crude collector. The pressurevessel also includes a second horizontal electrical grid assemblydisposed within the second compartment and aligned substantiallytransverse to a flow path extending from the transfer conduit to thecrude collection header.

These and other features will be more clearly understood from thefollowing detailed description taken in conjunction with theaccompanying drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, referenceis now made to the following brief description, taken in connection withthe accompanying drawings and detailed description, wherein likereference numerals represent like parts.

FIG. 1 illustrates a pressure vessel according to an embodiment of thedisclosure.

FIG. 2 illustrates an isometric view of the pressure vessel according tothe embodiment of FIG. 1.

FIG. 3 illustrates another isometric view of the pressure vesselaccording to the embodiment of FIG. 1.

FIG. 4 illustrates a third isometric view of the pressure vesselaccording to the embodiment of FIG. 1.

FIG. 5 illustrates a pressure vessel according to another embodiment ofthe disclosure.

FIG. 6 illustrates a pressure vessel according to yet another embodimentof the disclosure.

DETAILED DESCRIPTION

It should be understood at the outset that although illustrativeimplementations of one or more embodiments are illustrated below, thedisclosed systems and methods may be implemented using any number oftechniques, whether currently known or not yet in existence. Thedisclosure should in no way be limited to the illustrativeimplementations, drawings, and techniques illustrated below, but may bemodified within the scope of the appended claims along with their fullscope of equivalents.

The following brief definition of terms shall apply throughout theapplication:

The term “comprising” means including but not limited to, and should beinterpreted in the manner it is typically used in the patent context;

The phrases “in one embodiment,” “according to one embodiment,” and thelike generally mean that the particular feature, structure, orcharacteristic following the phrase may be included in at least oneembodiment of the present invention, and may be included in more thanone embodiment of the present invention (importantly, such phrases donot necessarily refer to the same embodiment);

If the specification describes something as “exemplary” or an “example,”it should be understood that refers to a non-exclusive example;

The terms “about” or “approximately” or the like, when used with anumber, may mean that specific number, or alternatively, a range inproximity to the specific number, as understood by persons of skill inthe art field; and

If the specification states a component or feature “may,” “can,”“could,” “should,” “would,” “preferably,” “possibly,” “typically,”“optionally,” “for example,” “often,” or “might” (or other suchlanguage) be included or have a characteristic, that particularcomponent or feature is not required to be included or to have thecharacteristic. Such component or feature may be optionally included insome embodiments, or it may be excluded.

Crude oil can be extracted from a well as a stream of fluids, which mayinclude not only the crude oil, but also other substances such as waterand gas. The well stream may also contain unwanted substances, such assalts. These unwanted substances can be carried as a mixture in thewater. The proportions of unwanted substances, water, gas, and oil inthe well stream may vary according to the circumstances of theparticular well over the life of the field. A mixture of water andunwanted substances may typically be in the form of droplets carried inthe oil. It may be desirable to isolate and remove at least some of thewater and unwanted substances from the crude oil. Separating the waterfrom the oil can remove most of the unwanted substances (e.g., salts)because these unwanted substances are dissolved in the water. Because itmay not be feasible to separate all of the water from the oil, the saltconcentration in the oil may be reduced to an acceptable level. Atypical two-stage desalting process can consist of two separate vesselsin connection with equipment external to each vessel for injection offreshwater or dilution water in between. Problems can arise with thisconfiguration because each vessel is large and heavy. Interconnectingpipes and other equipment also contribute to the overall size, weight,and costs. Frequently, the desalting process is carried out on aproduction platform where space and weight are at a premium.

Embodiments of the present disclosure include a multi-stage system forcrude oil desalting and dehydration in a single pressure vessel that isseparated into at least two different compartments via a sealedbulkhead. In an embodiment, each compartment may comprise at least oneof a vertical electrical grid assembly or a horizontal electrical gridassembly. Each grid assembly may comprise two or more electrical grids,where the electrical grids have at least two electrical grids with oneelectrical grid being energized at an applied voltage and the secondelectrical grid being at a different (or zero) voltage such that avoltage potential difference is created between the electrical grids,thereby causing the dispersed polarized water droplets in a crude oilstream to attract and coalesce. Each horizontal or vertical gridassembly may be energized by one or more electrical power transformers.Each electrical grid assembly may be powered by the same transformer orfrom different transformers that apply similar or differing highvoltage. For example, in some embodiments, an AC transformer may providefrom about 0 kilovolts (kV) to about 50 kV, or from about 0 kV to about40 kV, or from about 0 kV to about 30 kV, or from about 10 to about 25kV, and a DC transformer may provide from about negative 40 kV to about40 kV, or from about negative 20 kV to about 20 kV.

In some embodiments, the system comprises two or more electrical powertransformers that provide the pressure vessel's electrical gridassemblies with the same or different applied voltages. When AC currentis used, each electrical grid assembly may be configured to use twodifferent transformers operating out of phase with the other such thatthe separate electrical grids in one assembly are electrically out ofphase with each other. When electrical grids in the same electrical gridassembly use different transformers, each electrical grid may be ratedto withstand the same or different kilovolt-amperage (kVA), referred toas a KVA rating. Transformer(s) with a higher KVA rating may be usedwhen the oil stream comprises a high amount of emulsified water (e.g.,over 30% emulsified water by volume) because this oil stream can carrymore current. If alternating current is used to energize a gridassembly, the transformers may be configured as step-up transformersthat are in series with a current-limiting reactor. The drier the crudeoil stream becomes as it flows past the first electrical grid assemblyin the first compartment, through the transfer conduit into the secondcompartment, the more applied voltage is used to cause dropletcoalescence. Embodiments of the present disclosure provide a pressurevessel with adjustable electrical grids allowing the voltage potentialbetween electrical grids to be adjusted by adjusting the spacing betweenthe electrical grids themselves within each electrical grid assembly.This may allow the design to be varied as the fluid composition changesover time.

Embodiments of the pressure vessel include a dilution conduit configuredto allow for the injection and mixing of dilution fluid (e.g., a diluentsuch as water, a solvent, a polymer, etc. and/or demulsifying chemicals)between desalter stages and between compartments within the pressurevessel using a fluid mixer. Embodiments of the fluid mixer may include astatic mixer (e.g., a spiral nozzle or diffuser) or an externallyadjustable mixer, where the fluid mixer can be placed within thepressure vessel and in fluid communication with the transfer conduit.The transfer of the oil-water emulsion stream between compartments canbe accomplished entirely inside the pressure vessel via at least one ofan overflow weir or a collection header in order to provide intake for atransfer conduit which, in turn, passes through the sealed bulkheadwithin the pressure vessel. In some embodiments, the transfer of fluidscan pass between compartments through a conduit outside of the pressurevessel. In this embodiment, the mixer may be external to the pressurevessel. When fluids (e.g., a crude oil stream before or aftersupplemental dilution) are distributed into a compartment having ahorizontal electrical grid assembly (whether it be in the firstcompartment or second compartment of the pressure vessel), thedistribution can occur via a radial disc assembly directly between theelectrical grids of an electrical grid assembly or via a distributionheader of a distributor located under the bottom grid of the electricalgrid assembly.

In another embodiment of the present disclosure, a pressure vessel maybe configured to handle lighter crude oils (e.g., a crude oil streamhaving from 0-30% water by liquid volume) such that the firstcompartment comprises a horizontal electrical grid assembly (thus beingthe first stage) where the crude oil emulsion entering the first stagecomprises an inlet water content ranging from about 0-30% by liquidvolume. The horizontal electrical grid assembly may be powered with, forexample, one or more AC transformer(s). The oil-water emulsion exitingthe first stage (e.g., crude oil stream after passing through theenergized horizontal electrical grid assembly) can pass into thetransfer conduit and be mixed with fresh dilution water using the fluidmixer (e.g., static mixer disposed within the transfer conduit) andenter the second stage desalter (e.g., second compartment comprisingvertical grid section powered by, for example, a DC transformer). Thetransformer may be configured to operate at variable voltage to coalescethe remaining water droplets ranging from 1-5% by volume.

In some embodiments of the present disclosure, the pressure vessel mayinclude two or more vertical or horizontal electrical grid assemblies ina single compartment and have a dilution conduit that allows for theaddition of dilution fluid (e.g., a diluent such as water, recycledcoalesced water, etc.) for mixing by a fluid mixer before reachinganother compartment. It is understood that for each embodiment of apressure vessel, dilution fluid (e.g. a diluent such as fresh dilutionwater) may be added into the pressure vessel prior to the internal fluidmixer on the last stage of desalting. The effluent water from the laststage of desalting (e.g., last compartment within a pressure vessel) maybe withdrawn externally and pumped back to the stage immediatelypreceding the last stage (e.g., compartment immediately preceding thelast compartment). If such compartment is the first stage of the overallsystem, then the recycled water may be added externally to the oil-watermixture upstream of a fluid mixer before entering the pressure vesseland/or discarded.

Turning now to FIGS. 1-4, a system 100 for crude oil desalting anddehydration is disclosed. The system 100 comprises a pressure vessel 102defining a cavity 103 and extending along a central axis 101. Thepressure vessel 102 comprises a sealed bulkhead 114 disposed within thecavity 103. The sealed bulkhead 114 is configured to separate the cavity103 into a first compartment 104 and a second compartment 106. In anembodiment, the sealed bulkhead 114 is illustrated as a vertical wall orplate that separates the cavity and can be substantially orthogonal tothe central axis 101 or disposed at any other suitable angle. Forexample, the sealed bulkhead may be transverse and at a diagonal to thecentral axis (e.g., at an acute or obtuse angle relative to the centralaxis) instead of being substantially orthogonal. The sealed bulkhead maybe welded to form an internal seam with an internal wall of the pressurevessel 102 such that no liquid passage is permitted between the firstcompartment 104 and second compartment 106. In some embodiments, acontrolled fluid communication via a transfer conduit 132 can passthrough the sealed bulkhead, as further discussed below.

The pressure vessel 102 comprises a first distributor 108 disposedwithin the first compartment 104. The first distributor 108 isconfigured to receive a crude oil stream and provide fluid communicationinto the first compartment 104 via an inlet 110 of the first distributor108. In the embodiment illustrated in FIGS. 1-4, the first distributor108 comprises a distribution header 112 with multiple pipes havingperforations 115 that allow for fluid communication of the incomingcrude oil stream from the inlet 110 to the first compartment 104 alongflow path 128. The pressure vessel 102 may comprise a first flowconditioning baffle 116 disposed downstream of the first distributor108, and define holes in a pattern that is configured to help break upthe velocity profile and dampen turbulence of the crude oil streampassing through. The pressure vessel 102 may comprise a second flowconditioning baffle such as conditioning flow baffle 118, which can beoptionally grounded in some instances, that is downstream of the firstflow conditioning baffle 116. Hole patterns may be staggered on (andrelative to) each of the first flow conditioning baffle 116, flowconditioning baffle 118, so as to provide maximum flow straightening ofthe crude oil stream.

The second flow conditioning baffle 118 may also be used to provide avoltage differential for a first electrical grid assembly 122 that isdisposed within the first compartment 104. In some embodiments, thesecond flow conditioning baffle 118 can be grounded, though the secondflow conditioning baffle 118 can also be at a differential voltage otherthan ground in order to provide a voltage differential for the firstelectric grid assembly 122. The second flow conditioning baffle 118 mayhave a plurality of insulators around its perimeter holding the secondflow conditioning baffle 118 to the interior wall of the pressure vessel102 if the baffle 118 is optionally at a differential voltage than theelectrical grid 120. In some embodiments, the baffle 118 may bemechanically and/or electrically coupled to the interior wall of thepressure vessel 102 to ground the baffle 118 when the baffle 118 is usedat a ground potential. The first electrical grid assembly 122 alsocomprises at least one grid element (e.g., electrical grid 120) that isconfigured to be energized by a power transformer (e.g., an AC and/or DCtransformer). An electrical conduit 123 passes through the wall ofpressure vessel 102 to allow for an electrical wire to energize a gridelement (e.g., electrical grid 120). As the crude oil stream travelingalong flow path 128 passes the first conditioning baffle 116, firstelectrical grid assembly 122 is configured to create a first voltagepotential that electrostatically coalesces water from the crude oilstream into droplets before the intake 130 of the transfer conduit 132.

The first electrical grid assembly 122 comprises at least one electricalgrid 120 and at least one flow conditioning baffle 118. In someembodiments, the electrical grid 120 and the flow conditioning baffle118 may each be referred to as grid elements of an electrical gridassembly (e.g., first electrical grid assembly 122). In someembodiments, the shape and size of the electrical grid 120 may beconfigured in a shape that provides a surface area sufficient to producea voltage potential between 1% and 100% of the surface area of the flowconditioning baffle 118. The flow conditioning baffle 118 may begrounded (e.g., at zero voltage) or at a voltage that provides at leasta predefined voltage potential due to the relative voltage of electricalgrid 120. Each of the flow conditioning baffle 118 and the electricalgrid 120 are configured to define a plurality of openings in which flowpaths 128 (carrying the crude oil stream) may pass through. It isunderstood that a gap may exist between an electrical grid 120 and aflow conditioning baffle 118.

In some embodiments, the first electrical grid assembly 122 may comprisea spacing adjuster configured to vary a distance (i.e., the gap) betweenat least two of the grid elements (e.g., the electrical grid 120 and theflow conditioning baffle 118. For example, the spacing adjuster maycomprise a turnbuckle that adjusts the distance between the electricalgrid 120 and the flow conditioning baffle 118. Similarly, in someembodiments, the second electrical grid assembly 170 in the secondcompartment 106 may implement a spacing adjuster to vary the distance(e.g., gap) between grid elements making up the second electrical gridassembly 170 (e.g., gaps formed between grid 176 and electrical grids172, 174). Thus, in some embodiments, the first electrical grid assembly122 and second electrical grid assembly 170 may be referred to asadjustable electrical grid assemblies and each may be configured toallow the voltage potential between grid elements (e.g., between 120 and118, 174 and 176, or 172 and 176) to be adjusted by adjusting thespacing between the electrical grids themselves within each of the firstelectrical grid assembly 122 and second electrical grid assembly 170.The first electrical grid assembly 122 is disposed upstream from theintake 130 of the transfer conduit 132, specifically between the intake130 and at least a portion of the first distributor 108. In someembodiments, the first distributor 108 may include a radial distributionheader that is disposed between the flow conditioning baffle 118 andelectrical grid 120, and thus at all times, the first electrical gridassembly 122 is disposed between the intake 130 and at least a portionof first distributor 108.

The pressure vessel 102 may further comprise an overflow weir 126disposed within the first compartment 104. The overflow weir 126 isconfigured to define a passage 124 over the overflow weir 126, which inturn direct the crude oil stream from flow path 128 toward the intake130 of the transfer conduit 132. The overflow weir 126 is alsoconfigured to mitigate coalesced droplets (removed from the crude oilstream) from entering the intake 130 of the transfer conduit 132. Thismay be accomplished by the overflow weir 126 forming a seal with theinner walls of the pressure vessel 102 except through the passage 124,which is at an elevation that is higher than the water level formed fromthe coalesced droplets can reach. The coalesced droplets (e.g., water)may be removed from the first compartment 104 via outlets 144, 146.

The pressure vessel 102 further comprises transfer conduit 132 thatprovides fluid communication between the first compartment 104 and thesecond compartment 106. In some embodiments, the transfer conduit 132can be disposed within the cavity 103 and pass through the sealedbulkhead 114 from the first compartment 104 to the second compartment106. In other embodiments, the transfer conduit 132 can pass outside ofthe pressure vessel 102 from the first compartment and re-enter thepressure vessel 102 within the second compartment 106 to provide thefluid communication between the two compartments 104, 106. The secondcompartment 106 is in fluid communication with the first compartment 104via the transfer conduit 132. The transfer conduit 132 can comprise adistributor 134, which is configured to be a distribution headerarranged in an H-type configuration. In some embodiments, thedistributor 134 of the transfer conduit 132 has perforations 136 thatprovide fluid communication into the second compartment 106, where theperforations 136 can be on the sides of the distributor 134 (e.g.,between about 90 degrees and about 270 degrees relative to the verticalflow path 138 in the second compartment 106). Having perforations 136arranged on the sides of the distributor 134 can provide for ejection ofthe fluids in a horizontal direction, thereby minimizing maldistributionof the fluids, while also allowing for even distribution into the secondcompartment 106 and lower vertical flow velocity than if theperforations were in the same direction as the vertical flow path 138.

The pressure vessel 102 may further comprise a fluid mixer 140, wherethe fluid mixer 140 is in fluid communication with the transfer conduit132 and disposed between the intake 130 and the distributor 134 of thetransfer conduit 132. When the transfer conduit 132 is internal to thepressure vessel, the fluid mixer 140 can reside within the pressurevessel and within the first compartment 104. In some embodiments, thefluid mixer 140 may reside at another position along the transferconduit 132, such as at the sealed bulkhead 114 and/or within the secondcompartment 106. In some embodiments, the transfer conduit 132 maycomprise a pipe that houses the fluid mixer 140 along the fluidcommunication path therein. The fluid mixer 140 is illustrated as astatic mixer that is configured with spiraled ridges arrayed around thecentral axis of the fluid mixer 140. In other embodiments, the fluidmixer 140 may comprise a static mixer, an externally adjustable mixer,or a combination thereof.

The pressure vessel 102 may further comprise a dilution conduit 142 thatdefines a channel extending from outside the cavity 103 and into thetransfer conduit 132. The dilution conduit 142 may be configured tointroduce dilution fluid within the transfer conduit 132 and upstream ofthe fluid mixer 140. Dilution fluid can comprise at least one of adiluent such as an aqueous fluid (e.g., fresh water, recycled coalescedor separated water, etc.), a solvent, a polymer, or the like, or ademulsifier, or a combination thereof. A demulsifier may comprise achemical that aids in separation of the water from an emulsion of waterand crude oil and alters the kinetic stability by changing theinterfacial film encapsulating the water droplets to allow the waterdroplets to separate from the crude oil. The introduction of dilutionfluid via the dilution conduit 142 may assist in the demulsification ofthe crude oil stream passing through the transfer conduit and/or thefurther removal of salts from the crude oil. The arranged combination ofthe fluid mixer 140 agitating the crude oil stream, causing a change intemperature and/or pressure, the distributor 134 altering flow velocityvia perforations 136, and the first electrical grid assembly 122 andsecond electrical grid assembly 170 providing electrical coalescence viaelectrostatic fields which, upon being energized, can provide for a moreefficient dehydration and desalting system within the single pressurevessel 102.

The pressure vessel 102 further comprises a second electrical gridassembly 170 disposed within the second compartment 106. In someembodiments, the second electrical grid assembly 170 can be alignedsubstantially transverse to flow path 138. The flow path 138 can extendfrom the transfer conduit 132 (specifically after exiting from theperforations 136 of distributor 134) and vertically through the secondelectrical grid assembly 170 to the crude collection header 180. Thesecond electrical grid assembly 170 is disposed between the crudecollection header 180 and at least a portion of the transfer conduit132, specifically distributor 134. In some embodiments, distributor 134may comprise a radial distributor that is at least partially disposedbetween the electrical grid elements 172-176 of the second electricalgrid assembly 170. The second electrical grid assembly 170 comprises atleast two grid elements (e.g., electrical grids 172, 174, and grid 176)that each extend substantially orthogonal to the first electrical gridassembly 122. Put simply, the first electrical grid assembly 122 may bea vertical electrical grid assembly while the second electrical gridassembly is a horizontal electrical grid assembly. It is understoodthat, in some embodiments, the electrical grid assemblies (e.g., 122,170) may not be exactly vertical or horizontal, but rather be diagonalto the central axis, while also remaining orthogonal to their respectiveflow paths 128, 138 flowing there through.

The second electrical grid assembly 170 is configured to create a secondvoltage potential that electrostatically coalesces water into dropletsbefore the collection header 186 of crude collection header 180. Thesecond voltage potential created by the second electrical grid assembly170 (specifically between electrical grids 172 and 174 which areenergized by a power transformer, and a grid 176) can have a greaterabsolute magnitude than the first voltage potential created by the firstelectrical grid assembly 122 (specifically between electrical grid 120and the flow conditioning baffle 118 upon being energized by a powertransformer).

In some embodiments, second electrical grid assembly 170 comprises atleast two sets of electrical grids, such as electrical grid set 160(closer to the sealed bulkhead 114) and the second electrical grid set162. In some embodiments, the first electrical grid set 160 isconfigured to be electrically out of phase from the second electricalgrid set 162 in response to being energized by one or more powertransformers. Thus, as illustrated in FIGS. 1-4, the second electricalgrid assembly 170 comprises the first electrical grid set 160 and thesecond electrical grid set 162, where the first electrical grid set 160(and thus also the second electrical grid assembly 170) compriseselectrical grids 172, 174 and grid 176. The second electrical grid set162 may comprise electrical grids and a grid similar to that of thefirst electrical grid set 160.

In some embodiments, certain grids between the first electrical grid set160 and the second electrical grid set 162 can be electrically coupled.The interconnection can allow for power configurations to allow theelectrical energy to be out of phase between the two grid sets 160, 162.For example, a central grid in the first electrical grid set 160 can beelectrically coupled to one or more of the grids (e.g., grid 172 and/orgrid 174) of the second electrical grid set 162. This may provide foradditional separation power between the stacked grids 172, 176 and/orbetween stacked grids 174, 176.

The second electrical grid assembly 170 can be formed from any suitableconductive material that provides for pores or openings through whichthe fluids can pass. In some embodiments, the grids in the secondelectrical grid assembly 170 can comprise screens, perforated plates,mesh, or the like. In some embodiments, at least a portion of the gridsin the second electrical grid assembly 170 can be formed from one ormore hollow conductive tubes. The tubes can be electrically coupled toform a grid assembly. In some embodiments, the tubes can have an outerdiameter on the order of 0.25 inches to about 2 inches, or between about0.5 inches to about 1.5 inches, and the tubes can be formed from aconductive material such as metal, alloy, or other type of material. Theuse of hollow tubes provides for a large contact area while remaininglightweight.

Electrical conduits 152, 154 may pass electrical wires through the wallof the pressure vessel 102 while electrically insulating the wires fromthe vessel itself, and electrically couple the wires to the secondelectrical grid assembly 170 via electrical grids 172 and 174. Grid 176may be disposed between electrical grids 172 and 174. The grid 176 mayallow for a voltage potential to be created within the second electricalgrid assembly 170 via an electrical connection. The electricalconnection can be coupled to a power source when the grid 176 is at adifferential voltage or a grounding wire when the grid 176 is at groundpotential. As discussed above, in some embodiments, the distance betweenthe electrical grids 172, 174 and grid 176 may be adjustable, therebyallowing dynamic variation of the electrical field and voltage potentialto provide additional droplet coalescence in the second compartment 106.Water and other effluent that is coalesced into droplets may falltowards and past the transfer conduit's 132 distributor 134 and exit thepressure vessel via outlets 148, 150.

The pressure vessel 102 further comprises a crude collection header 180disposed within the second compartment 106. The pressure vessel 102 canbe configured to provide a pressure differential between inlet 110 ofthe first distributor 108 and the outlet 182 of the crude collectionheader 180, thereby allowing for the communication of fluid (e.g., thecrude oil stream) along flow path 128, through the transfer conduit 132,and along flow path 138, which exits the pressure vessel 102 via outlet182. The crude collection header 180 comprises a collection header 186,outlet 182, and perforations 184 defined by the collection header 186.The collection header 186 is configured to communicate the crude oilstream (after it is passed across the second electrical grid assembly170) out of the second compartment 106 via the outlet 182 of the crudecollection header 180.

Turning now to FIG. 5, a system 200 for desalting and dehydrating crudeoil is disclosed according to an embodiment of the present disclosure.The system 200 comprises pressure vessel 202. The pressure vessel 202can be the same or similar to the pressure vessel 102 described withrespect to FIGS. 1-4, and the discussion with respect to the pressurevessel 102 can apply with respect to the pressure vessel 202. As shownin FIG. 5, the pressure vessel 202 comprises a sealed bulkhead 208disposed within a cavity 203 defined by the pressure vessel 202, wherethe sealed bulkhead 208 is configured to divide the cavity 203 into afirst compartment 204 and a second compartment 206. A first distributor210 is disposed within the first compartment 204, and the firstdistributor 210 is configured to receive a crude oil stream via inlet212, and in turn providing fluid communication of the crude oil streaminto the first compartment 204 via perforations 214 of the firstdistributor 210. In some embodiments, the distributor 210 includes apipe extending along central axis 201, between the sealed bulkhead 208and an end of the pressure vessel. The inlet 212 may be oriented in adirection substantially parallel to the flow path 216, which isorthogonal to an electrical grid assembly (e.g., horizontal electricalgrid assembly 230). To reduce flow velocity and provide a more evendistribution of the crude oil stream within the first compartment 204,the distributor 210 may be configured with a plurality of perforations214 defined along the side (e.g., aligned between about 90 degrees andabout 270 degrees relative to the inlet 212), thereby initially ejectingfluids horizontally within the pressure vessel before the fluid alignvertically along flow path 216.

The pressure vessel 202 further comprises a horizontal electrical gridassembly 230 disposed within the first compartment 204. The horizontalelectrical grid assembly 230 is disposed substantially parallel to thecentral axis 201 and located between the collection header 242 of thetransfer conduit 240 and at least a portion of the first distributor210. The horizontal electrical grid assembly 230 can be the same orsimilar to the horizontal electrical grid assembly 170, and any of theconsiderations described with respect to the horizontal grid assembly170 can also apply to the horizontal electrical grid assembly 230. Thehorizontal electrical grid assembly 230 is downstream of the firstdistributor 210 and disposed within the first compartment such that flowpath 216 of the crude oil stream is substantially orthogonal to theelectrical grid elements (e.g., electrical grids 232, 234, and grid 236)of horizontal electrical grid assembly 230. The horizontal electricalgrid assembly 230 comprises at least two grid elements, with at leastone of them configured to be energized. For example, the horizontalelectrical grid assembly 230 is configured to be energized by a powertransformer unit, such as alternating current (AC) power transformer 50.In some embodiments, electrical conduits may allow for wiring 52 to passthrough the wall of the pressure vessel 202 and electrically couple toone or more electrical grid elements, such as electrical grids 232 and234.

Two or more of the electrical grid elements, such as electrical grids232, 234, and 236, may comprise conductive metal grids that are operablefor being energized to a first potential, and while a third electricalgrid element may be at a differential voltage potential. For example,one of the grids can be grounded via a grounding wire 54, therebyallowing the grid 236 to have a zero voltage. In other embodiments, thegrids can be placed at differential voltages so that a voltage potentialexists between the grids without having any of the grids grounded. Withthe grid 236 being disposed between electrical grids 232 and 234, thehorizontal electrical grid assembly 230 can be configured to create afirst voltage potential that electrostatically coalesces water from thecrude oil stream (travelling along flow path 216) into droplets beforereaching the collection header 242 of the transfer conduit 240. In someembodiments, the horizontal electrical grid assembly 230 comprises aspacing adjuster configured to vary a distance between at least two ofthe grid elements, such as between electrical grid 232 and grid 236, orelectrical grid 234 and grid 236. The pressure vessel 202 is configuredto remove droplets that are coalesced out of the crude oil streampassing along flow path 216 via outlets 218 and 220. In someembodiments, at least a portion of the effluent water may be used as adilution fluid that is injected via a dilution conduit. While threegrids 232, 234, and 236 are shown as making up the horizontal gridassembly 230, only two grids, or more than three grids can be used toform the horizontal grid assembly 230, including being arranged inseries and/or parallel.

The pressure vessel 202 comprises a transfer conduit 240 that can bedisposed within the cavity 203, and passes through the sealed bulkhead208 from the first compartment 204 to the second compartment 206. Insome embodiments, a portion of the transfer conduit 240 can pass outsideof the pressure vessel 202. The transfer conduit 240 comprises acollection header 242 configured to receive the crude oil stream viaperforations 244. The crude oil stream may be received in the transferconduit 240 from the flow path 216 in first compartment 204 and providefluid communication along flow path 238 to the second compartment 206.The pressure vessel 202 may comprise a fluid mixer 248 that is in fluidcommunication with the transfer conduit 240 and disposed between anintake of the transfer conduit (e.g., perforations 244 in collectionheader 242) and a distributor 250 of the transfer conduit 240. The crudeoil stream passing from the first compartment 204 through transferconduit 240 and the fluid mixer 248, may exit into the secondcompartment 206 via a plurality of perforations 246 defined bydistributor 250 of transfer conduit 240. The fluid mixer 248 maycomprise a static mixer, an externally adjustable mixer, or acombination thereof. In some embodiments, the pressure vessel 202further comprises a dilution conduit that defines a channel extendingfrom outside the cavity 203 and into the transfer conduit 240. Thedilution conduit may be configured to introduce dilution fluid into thetransfer conduit 240 and upstream of the fluid mixer 248. Dilution fluidmay comprise at least one of water, a demulsifier, or a combinationthereof.

The pressure vessel 202 further comprises a vertical electrical gridassembly 260 disposed within the second compartment 206. The verticalelectrical grid assembly 260 may be disposed between the overflow weir228 and at least a portion of the transfer conduit 240, such as aportion of distributor 250. The vertical grid assembly 260 may bealigned substantially transverse to a horizontal flow path 254, in whichthe flow path 254 extends from the transfer conduit 240 to an overflowweir 228. The vertical electrical grid assembly 260 comprises an arrayof vertically parallel electrical grid elements (e.g., electrical grids262, 264, and grids 266, 268), where the each of the grid elements areorthogonal to the flow path 254 carrying the crude oil stream. In someembodiments, the second compartment 206 may comprise a flow conditioningbaffle 252, which includes a perforated plate that defines holes throughwhich the crude oil stream can pass while traveling along the flow path254.

The vertical electrical grid assembly 260 is energized by a directcurrent (DC) power transformer 60 via wiring 62 that may pass through anelectrical conduit of the pressure vessel 202. In some embodiments, thevertical electrical grid assembly 260 comprises at least two gridelements (e.g., any of 262-268), with each grid element extendingsubstantially orthogonal to the horizontal electrical grid assembly 230(e.g., transverse to the central axis 201). The vertical electrical gridassembly 260, upon being energized by DC power transformer 60, isconfigured to create a voltage potential that electrostaticallycoalesces water into droplets before the overflow weir 228. This voltagepotential may be created by the DC power transformer 60 applying avoltage to electrical grids 262 and 264, while grids 266 and 268 remainat a different voltage potential. For example, the grids 266, 268 can begrounded (thus at zero voltage), thereby creating voltage potential.However, in some embodiments, the grids 266, 268 can be energized with adifferent voltage (e.g., a negative voltage, a different positivevoltage, etc.) to create the voltage potential between the grids. Insome embodiments, the grids 266, 268 may not be at exactly zero voltage,but rather at a predefined voltage such that a voltage differential iscreated so as to provide electrical coalescence. Each of the grids 266,268 and electrical grids 262, 264 define holes through which the crudeoil flowing along horizontal flow path 254 may pass.

In some embodiments, the crude oil stream comprises an emulsion thatenters the first compartment 204 with a water content ranging from zeroto approximately 30% by liquid volume. In some embodiments, the DC powertransformer 60 may energize the vertical electrical grid assembly 260 tooperate at variable voltage in order to coalesce the remaining waterdroplets and yield a crude oil stream (after passing through thevertical electrical grid assembly along flow path 254) that has a watercontent ranging from about 0-5% by liquid volume (thus yielding a driercrude oil stream exiting the crude outlet 280 than when it entered viainlet 212. The voltage potential created by the vertical electrical gridassembly 260 upon being energized may be referred to as a second voltagepotential and the voltage potential created by the horizontal electricalgrid assembly 230 may be referred to as a first voltage potential.Because the crude oil stream may be drier when entering the secondcompartment 206 (e.g., the water content by fluid volume in the crudeoil stream being less due to droplet coalescence from at least thehorizontal electrical grid assembly 230), the vertical electrical gridassembly 260 may have higher applied secondary voltage rating and/orapplied voltage differential across the vertical electrical gridassembly 260 than the horizontal electrical grid assembly 230, and thusthe vertical electrical grid assembly 260 may be capable of providing ahigher voltage potential in order to electrically coalesce water thanthe voltage potential created by the horizontal electrical grid assembly230. The coalesced droplets of water and other effluent coalesced fromthe crude oil stream may exit from the second compartment 206 via one ormore of the outlets 222, 224, and 226.

The pressure vessel 202 further comprises an overflow weir 228 that isdisposed within the second compartment 206. The overflow weir 228 isdownstream of the vertical electrical grid assembly 260 and isconfigured to mitigate coalesced droplets (removed from the crude oilstream) from passing over the overflow weir 228 and exiting crude outlet280. This may be accomplished by the overflow weir 228 forming a sealwith the inner walls of the pressure vessel 202 around a lower portionof the overflow weir 228, thereby directing flow path 254 through thepassage 270, which is at an elevation (relative to the central axis 201)that is higher than the coalesced fluid can reach. After passing throughthe passage 270 and over the overflow weir 228, the crude oil stream mayexit via crude outlet 280 of the pressure vessel 202. It is understoodthat pressure vessel 202 is configured to withstand a pressuredifferential between crude outlet 280 and inlet 212 of first distributor210, such that the crude oil stream exits via the crude outlet 280 withless water content by liquid volume than when it entered via inlet 212.

Turning now to FIG. 6, a system 300 for desalting and dehydrating crudeoil is disclosed according to another embodiment of the presentdisclosure. The system 300 comprises a pressure vessel 302 extendingalong central axis 301 while also defining a cavity 305. The pressurevessel 302 comprises a sealed bulkhead 308 disposed within the cavity305 defined by the pressure vessel 302. The sealed bulkhead 308 isconfigured to divide the cavity into a first compartment 304 and asecond compartment 306. The pressure vessel further comprises at leastone distributor 310, 318 disposed within the first compartment 304. Thedistributors 310, 318 are configured to receive a crude oil stream viainlets 314 and 316, respectively, and provide fluid communication intothe first compartment 304 via perforations 312 defined by thedistributor 310. While two distributors are shown, only one suchdistributor may be used in some embodiments. As illustrated in FIG. 6,distributor 310 is configured as a pipe distributor and distributor 318is configured as a radial distributor having a first radial outlet 320and a second radial outlet 322. The distributor 310 can be disposedupstream from the horizontal electrical grid assembly 332, while thedistributor 318 is at least partially disposed between electrical gridelements, specifically the first radial outlet 320 being disposedbetween electrical grids 334 and 338, and the second radial outlet 322being disposed between electrical grids 334 and 336. Each of the firstradial outlet 320 and second radial outlet 322 of distributor 318 isconfigured to eject a crude oil stream into the first compartment 304 atan orientation substantially parallel to the horizontal electrical gridassembly 332 and transverse to the flow path 303.

The pressure vessel 302 comprises horizontal electrical grid assembly332 that is disposed within the first compartment 304. The horizontalelectrical grid assembly 332 can be the same or similar to the secondhorizontal electrical grid assembly 170 described with respect to FIGS.1-4, and any of the consideration described with respect to the secondhorizontal electrical grid assembly 170 can be used with the horizontalelectrical grid assembly 332. The horizontal electrical grid assembly332 is disposed within the first compartment 304 at an elevation betweenthe collection header 342 of the transfer conduit 344 and at least oneof the plurality of distributors 310, 318. The horizontal electricalgrid assembly 332 can be energized by two or more alternating current(AC) power transformers (e.g., 20, 30). The horizontal electrical gridassembly 332 comprises at least three grid elements. The first AC powertransformer 20 may energize electrical grid 336 via wiring 22, andsecond AC power transformer 30 may energize electrical grid 334 viawiring 32.

The AC power transformers 20, 30 may operate at the same or differentfrequency and may be in or out of phase each other. The electrical grid338 may serve as a grounding grid when it is grounded via wiring 340,and thus at zero voltage. In some embodiments, the electrical grid 338may be at a potential other than ground. In some embodiments, whenelectrical grid 334 is energized, it produces an electric field that isout of phase with the adjacent electrical grid 336 (which is energizedby AC power transformer 20). In some embodiments, the electric field canbe out of phase by between about 120 degrees (e.g., with three-phasepower) and about 180 degrees (e.g., for two-phase power). The horizontalelectrical grid assembly 332 is configured to create at least a firstvoltage potential that electrostatically coalesces water from the crudeoil stream into droplets before the collection header 342 of thetransfer conduit 344. The horizontal electrical grid assembly 332 mayalso create another voltage potential either due to electrical grids 336and 334 being energized with different voltages and/or due to electricalgrids 336, 334 being out of phase with each other. The pressure vessel302 is configured to remove droplets that are coalesced out of the crudeoil stream passing along flow path 303 via outlets 324 and 326.

The use of one or more radial outlets 320, 322 being disposed within thehorizontal electrical grid assembly 332 and the distributor 310 havingperforations 312 that are horizontal to the flow path 303 (e.g., comingout of the sides of the distributor 310 instead of the top) can resultin a lower velocity flow of crude oil stream traveling along flow path303, thereby allowing more time for electrical coalescence by horizontalelectrical grid assembly 332. It is understood that the electrical grids334, 336, and 338 of horizontal electrical grid assembly 332 andelectrical grids 366, 368, and grid 370 of horizontal electrical gridassembly 364 are configured in a perforated grid that can conditionfluid flow and provides the structure for electrical coalescence in eachof the first compartment 304 and second compartment 306, respectively.In some embodiments, at least one of the horizontal electrical gridassembly 332, 364 can comprise a spacing adjuster configured to vary adistance between at least two of the grid elements, such as any ofelectrical grids 334, 336, and 338 of horizontal electrical gridassembly 332 or electrical grids 366, 368, and grid 370 the secondhorizontal electrical grid assembly 364.

The pressure vessel 302 further comprises a transfer conduit 344 that isdisposed within the cavity 305 and passes through the sealed bulkhead308 from the first compartment 304 to the second compartment 306. Thetransfer conduit 344 comprises a collection header 342 configured toreceive the crude oil stream into the transfer conduit 344 viaperforations 346, and provide fluid communication from the firstcompartment 304 to the second compartment 306. The transfer conduit 344may comprise a distributor 360, which is configured as a pipedistributor having a plurality of perforations 362 to eject the crudeoil stream into the second compartment 306. The perforations 362 may bedefined along the side of the distributor 360 such that the crude oilstream is initially ejected horizontally before flowing vertically alongflow path 352 towards the second horizontal electrical grid assembly364.

The pressure vessel 302 may further comprise a fluid mixer 350 disposedwithin the pressure vessel 302 and in fluid communication with thetransfer conduit 344. The fluid mixer 350 is disposed between thecollection header 342 of the transfer conduit 344 and the distributor360 of the transfer conduit 344 disposed in the second compartment 306.In some embodiments, the fluid mixer comprises a static mixer (e.g., anozzle, spiral nozzle) and/or an externally adjustable mixer (e.g., anexternally adjustable nozzle that varies the incoming and/or outgoingaperture of the nozzle). In some embodiments, the pressure vessel 302may comprise a dilution conduit 348 that is disposed upstream from thefluid mixer 350.

The pressure vessel 302 further comprises a second horizontal electricalgrid assembly 364 disposed within the second compartment 306 and alignedsubstantially transverse to a flow path 352, where the flow path 352 isextending from the distributor 360 of the transfer conduit 344 to thecrude collection header 378 of the crude collector 372. The secondhorizontal electrical grid assembly 364 is disposed between the crudecollection header 378 and at least a portion of the transfer conduit344, specifically distributor 360. The second horizontal electrical gridassembly 364 comprises a plurality of electrical grids, such aselectrical grids 366 and 368. The second horizontal electrical gridassembly 364 also has at least one electrical grid such as grid 370 thatcan be at a different voltage potential. In some embodiments, the grid370 can be at a ground potential, while in other embodiments, the grid370 can be at a different potential that the remaining grids to create avoltage difference between the grids. AC power transformer 40 mayenergize electrical grids 366 and 368 via wiring 42, and grid 370 may beconfigured to be grounded via wiring 44 (thus resulting in a zerovoltage that allows for voltage potentials to be created). Thus, thesecond horizontal electrical grid assembly 364 is configured to create asecond voltage potential that electrostatically coalesces water intodroplets before the crude collection header 378 in the secondcompartment 306. The second voltage potential created by the secondhorizontal electrical grid assembly 364 can be greater than the firstvoltage potential created by the first horizontal electrical gridassembly 332 in the first compartment 304. The second horizontalelectrical grid assembly 364 can be energized by an AC power transformerthat provides a voltage differential to electrical grids 366, 368 thatis higher than the voltage differential provided by AC powertransformers 20 and 30.

The pressure vessel 302 is configured to remove droplets that arecoalesced out of the crude oil stream passing along flow path 352 in thesecond compartment 306 via outlets 328 and 330. The pressure vessel 302further comprises a crude collector 372 disposed within the secondcompartment 306. The crude collector 372 comprises a crude collectionheader 378 configured to receive the crude oil stream via perforations374 after the second horizontal electrical grid assembly 364electrically coalesces water into droplets for removal from the secondcompartment 306. The crude collector 372 is configured to communicatefluid out of the second compartment 306 to an outlet 376 of the crudecollector 372.

The present disclosure includes methods of desalting and dehydratingcrude oil via a single pressure vessel, such as any one of pressurevessel 102 of FIGS. 1-4, pressure vessel 202 of FIG. 5, and/or pressurevessel 302 of FIG. 6. The method comprises receiving a crude oil streaminto a first distributor disposed within a first compartment of apressure vessel, where the first compartment is separated from a secondcompartment by a sealed bulkhead, and the first compartment comprises afirst electrical grid assembly. The method continues by injecting,within the first compartment via the first distributor, the crude oilstream before at least a portion of the first electrical grid assemblyalong a first flow path.

Next, the method may continue with electrostatically coalescing, bypassing the diluted crude oil stream through the first electrical gridassembly being energized to a first voltage potential, water from thecrude oil stream into droplets. The method further comprises preventing,within the first compartment, coalesced droplets from entering an intakeof a transfer conduit by separating the coalesced droplets from theintake of the transfer conduit. The transfer conduit can optionally bewithin the pressure vessel and pass through the sealed bulkhead suchthat the transfer conduit fluidly communicates the crude oil stream fromthe first compartment to the second compartment. In some embodiments,preventing coalesced droplets from entering the intake of the transferconduit is based on an overflow weir separating the coalesced dropletsfrom the intake of the transfer conduit. In other embodiments,preventing coalesced droplets from entering the intake of the transferconduit is based on the intake of the transfer conduit being disposedwithin the first compartment at an elevation above the first electricalgrid assembly.

The method also includes transferring the crude oil stream to the secondcompartment via the transfer conduit. Transferring may comprisedirecting, via an overflow weir, the crude oil stream from the firstflow path and towards the intake of the transfer conduit. The methodcontinues with diluting, via a dilution conduit and a fluid mixer inlinewith the transfer conduit, the crude oil stream in the transfer conduitwith water. In some embodiments, diluting comprises introducing waterinto the transfer conduit via the dilution conduit and mixing the crudeoil stream with the water via the fluid mixer. Introducing the water mayoccur upstream from the fluid mixer. Subsequent to diluting, the methodcontinues with distributing, via a distributor of the transfer conduitin the second compartment, the diluted crude oil stream before at leasta portion of a second electrical grid assembly. In some embodiments,distributing comprises ejecting the diluted crude oil stream at anorientation substantially orthogonal to a second flow path in the secondcompartment.

The method further includes electrostatically coalescing, by passing thediluted crude oil stream through the second electrical grid assemblybeing energized to a second voltage potential, water from the dilutedcrude oil stream into droplets. In some embodiments, the secondelectrical grid assembly comprises at least two grid elements that eachextend substantially orthogonal to the first electrical grid assembly.Subsequent to the electrostatically coalescing, the method may continuewith removing crude oil from the second compartment via a crudecollector disposed within the second compartment. In some embodiments,the method includes removing the coalesced droplets from firstcompartment via an outlet in the vessel. In some embodiments, the methodmay also further comprise removing the coalesced droplets from secondcompartment via a second outlet in the pressure vessel.

Having described various devices, systems, and methods, some embodimentscan include, but are not limited to:

In a first embodiment, a system for crude oil desalting and dehydrationcomprises: a pressure vessel defining a cavity and extending along acentral axis, the pressure vessel comprising: a sealed bulkhead disposedwithin the cavity, the sealed bulkhead separating the cavity into afirst compartment and a second compartment; a first distributor disposedwithin the first compartment, wherein the first distributor isconfigured to receive a crude oil stream and provide fluid communicationinto the first compartment via an inlet of the first distributor; atransfer conduit that is disposed within the cavity, the secondcompartment being in fluid communication with the first compartment viathe transfer conduit; a first electrical grid assembly disposed withinthe first compartment, the first electrical grid assembly disposedbetween an intake of the transfer conduit and at least a portion of thefirst distributor; a crude outlet disposed within the secondcompartment, the crude outlet configured to communicate the crude oilout of the second compartment; a second electrical grid assemblydisposed within the second compartment, wherein the second electricalgrid assembly is not aligned with the first electrical grid assembly.

A second embodiment can include the system of the first embodiment,further comprising a fluid mixer, wherein the fluid mixer is in fluidcommunication with the transfer conduit and disposed between an intakeof the transfer conduit and a distributor of the transfer conduit.

A third embodiment can include the system of the second embodiment,wherein the fluid mixer comprises a static mixer or an externallyadjustable mixer.

A fourth embodiment can include the system of any of the first to thirdembodiments, wherein the first electrical grid assembly is configured tobe energized by a power transformer.

A fifth embodiment can include the system of any of the first to fourthembodiments, wherein the first electrical grid assembly is configured tocreate a first voltage potential that electrostatically coalesces waterfrom the crude oil stream into droplets before the intake of thetransfer conduit.

A sixth embodiment can include the system of any of the first to fourthembodiments, wherein the first electrical grid assembly comprises atleast two grid elements and a spacing adjuster configured to vary adistance between at least two of the grid elements.

A seventh embodiment can include the system of any of the first to sixthembodiments, wherein the pressure vessel further comprising an overflowweir disposed within the first compartment, wherein the overflow weir isconfigured to define a passage over the weir that directs the crude oilstream toward the intake of the transfer conduit and mitigates coalesceddroplets from entering the intake of the transfer conduit.

An eighth embodiment can include the system of any of the first toseventh embodiments, wherein the second electrical grid assembly isdisposed between the crude collection header and at least a portion ofthe transfer conduit.

A ninth embodiment can include the system of any of the first to eighthembodiments, wherein the second electrical grid assembly comprises atleast two grid elements that each extend substantially orthogonal to thefirst electrical grid assembly.

A tenth embodiment can include the system of any of the first to ninthembodiments, wherein the second electrical grid assembly is configuredto create a second voltage potential that electrostatically coalesceswater into droplets before the crude collection header.

An eleventh embodiment can include the system of any of the first totenth embodiments, wherein the second voltage potential created by thesecond electrical grid assembly is greater than the first voltagepotential created by the first electrical grid assembly.

A twelfth embodiment can include the system of any of the first toeleventh embodiments, wherein the second electrical grid assemblycomprises a first set of electrical grids and a second set of electricalgrids.

A thirteenth embodiment can include the system of the twelfthembodiment, wherein the first set is configured to be electrically outof phase from the second set of electrical grids in response to beingenergized by a power transformer.

A fourteenth embodiment can include the system of any of the first tothirteenth embodiments, wherein the pressure vessel further comprising adilution conduit that defines a channel extending from outside thecavity and into the transfer conduit.

A fifteenth embodiment can include the system of the fourteenthembodiment, wherein the dilution conduit is configured to introducedilution fluid within the transfer conduit and upstream of the fluidmixer.

A sixteenth embodiment can include the system of the fifteenthembodiment, wherein the dilution fluid comprises at least one of water,a demulsifier, or a combination thereof.

In a seventeenth embodiment, a method of desalting and dehydrating crudeoil via a single pressure vessel comprises: receiving a crude oil streaminto a first distributor disposed within a first compartment of apressure vessel, the first compartment being separated from a secondcompartment by a sealed bulkhead, the first compartment comprising afirst electrical grid assembly; injecting, within the first compartmentvia the first distributor, the crude oil stream before at least aportion of the first electrical grid assembly along a first flow path;electrostatically coalescing, by passing the diluted crude oil streamthrough the first electrical grid assembly being energized to a firstvoltage potential, water from the crude oil stream into droplets;preventing, within the first compartment, coalesced droplets fromentering an intake of a transfer conduit by separating the coalesceddroplets from the intake of the transfer conduit, wherein the transferconduit is within the pressure vessel and passes through the sealedbulkhead and fluidly communicates the crude oil stream from the firstcompartment to the second compartment; transferring the crude oil streamto the second compartment via the transfer conduit; diluting, via adilution conduit and a fluid mixer in-line with the transfer conduit,the crude oil stream in the transfer conduit with water; subsequent todiluting, distributing, via a distributor of the transfer conduit in thesecond compartment, the diluted crude oil stream before at least aportion of a second electrical grid assembly; electrostaticallycoalescing, by passing the diluted crude oil stream through the secondelectrical grid assembly being energized to a second voltage potential,water from the diluted crude oil stream into droplets; subsequent to theelectrostatically coalescing, removing crude oil from the secondcompartment via a crude collector disposed within the secondcompartment.

An eighteenth embodiment can include the method of the seventeenthembodiment, wherein preventing coalesced droplets from entering theintake of the transfer conduit is based on an overflow weir separatingthe coalesced droplets from the intake of the transfer conduit.

A nineteenth embodiment can include the method of the seventeenthembodiment, wherein preventing coalesced droplets from entering theintake of the transfer conduit is based on the intake of the transferconduit being disposed within the first compartment at an elevationabove the first electrical grid assembly.

A twentieth embodiment can include the method of any of the seventeenthto nineteenth embodiments, further comprising removing the coalesceddroplets from first compartment via an outlet in the vessel.

A twenty first embodiment can include the method of any of theseventeenth to twentieth embodiments, wherein transferring comprisesdirecting, via an overflow weir, the crude oil stream from the firstflow path and towards the intake of the transfer conduit.

A twenty second embodiment can include the method of any of theseventeenth to twenty first embodiments, wherein diluting comprisesintroducing water into the transfer conduit via the dilution conduit andmixing the crude oil stream with the water via the fluid mixer.

A twenty third embodiment can include the method of any of theseventeenth to twenty second embodiments, wherein introducing the wateroccurs upstream from the fluid mixer.

A twenty fourth embodiment can include the method of any of theseventeenth to twenty third embodiments, wherein distributing comprisesejecting the diluted crude oil stream at an orientation substantiallyorthogonal to a second flow path in the second compartment.

A twenty fifth embodiment can include the method of any of theseventeenth to twenty fourth embodiments, wherein the second electricalgrid assembly comprises at least two grid elements that each extendsubstantially orthogonal to the first electrical grid assembly.

A twenty sixth embodiment can include the method of any of theseventeenth to twenty fifth embodiments, further comprising removing thecoalesced droplets from second compartment via a second outlet in thevessel.

In a twenty seventh embodiment, a pressure vessel for crude oildesalting and dehydration comprises: a sealed bulkhead disposed within acavity defined by the pressure vessel, the sealed bulkhead configured todivide the cavity into a first compartment and a second compartment; afirst distributor disposed within the first compartment, wherein thefirst distributor is configured to receive a crude oil stream andprovide fluid communication into the first compartment via an inlet ofthe first distributor; a transfer conduit that is disposed within thecavity and passes through the bulkhead from the first compartment to thesecond compartment, wherein the transfer conduit comprises a collectionheader configured to receive the crude oil stream from the firstcompartment and provide fluid communication to the second compartmentvia the transfer conduit; a horizontal electrical grid assembly disposedwithin the first compartment, the horizontal electrical grid assemblydisposed between the collection header of the transfer conduit and atleast a portion of the first distributor; an overflow weir disposedwithin the second compartment, wherein the overflow weir is configuredto define a passage over the weir that directs the crude oil streamtoward a crude outlet and mitigate coalesced droplets from passing overthe overflow weir; and a vertical electrical grid assembly disposedwithin the second compartment and aligned substantially transverse to ahorizontal flow path extending from the transfer conduit to the overflowweir, wherein the vertical electrical grid assembly is energized by adirect current (DC) power transformer.

A twenty eight embodiment can include the system of the twenty seventhembodiment, further comprising a fluid mixer that is in fluidcommunication with the transfer conduit and disposed between an intakeof the transfer conduit and a distributor of the transfer conduit.

A twenty ninth embodiment can include the system of the twenty eighthembodiment, wherein the fluid mixer comprises a static mixer, whereinthe fluid mixer comprises an externally adjustable mixer.

A thirtieth embodiment can include the system of any of the twentyseventh to twenty ninth embodiments, wherein the horizontal electricalgrid assembly is energized by an alternating current (AC) powertransformer.

A thirty first embodiment can include the system of any of the twentyseventh to thirtieth embodiments, wherein the horizontal electrical gridassembly is configured to create a first voltage potential thatelectrostatically coalesces water from the crude oil stream intodroplets before the collection header of the transfer conduit.

A thirty second embodiment can include the system of any of the twentyseventh to thirty first embodiments, wherein the horizontal electricalgrid assembly comprises at least two grid elements and a spacingadjuster configured to vary a distance between at least two of the gridelements.

A thirty third embodiment can include the system of any of the twentyseventh to thirty second embodiments, wherein the vertical electricalgrid assembly comprises at least two grid elements that each extendsubstantially orthogonal to the first electrical grid assembly.

A thirty fourth embodiment can include the system of any of the twentyseventh to thirty third embodiments, wherein the vertical electricalgrid assembly is configured to create a second voltage potential thatelectrostatically coalesces water into droplets before the overflowweir.

A thirty fifth embodiment can include the system of any of the twentyseventh to thirty fourth embodiments, wherein the second voltagepotential created by the vertical electrical grid assembly is greaterthan the first voltage potential created by the horizontal electricalgrid assembly.

A thirty sixth embodiment can include the system of any of the twentyseventh to thirty fifth embodiments, wherein the pressure vessel furthercomprising a dilution conduit that defines a channel extending fromoutside the cavity and into the transfer conduit.

A thirty seventh embodiment can include the system of the thirty sixthembodiment, wherein the dilution conduit is configured to introducedilution fluid within the transfer conduit and upstream of the fluidmixer.

A thirty eighth embodiment can include the system of the thirty seventhembodiment, wherein the dilution fluid comprises at least one of water,a solvent, a polymer, a demulsifier, or a combination thereof.

A thirty ninth embodiment can include the system of any of the twentyseventh to thirty eighth embodiments, wherein the vertical electricalgrid assembly is disposed between the overflow weir and at least aportion of the transfer conduit.

In a fortieth embodiment, a pressure vessel for crude oil desalting anddehydration comprises: a sealed bulkhead disposed within a cavitydefined by the pressure vessel, the sealed bulkhead configured to dividethe cavity into a first compartment and a second compartment; aplurality of distributors disposed within the first compartment, whereineach of the plurality of distributors is configured to receive a crudeoil stream and provide fluid communication into the first compartmentvia inlets; a transfer conduit that is disposed within the cavity andpasses through the bulkhead from the first compartment to the secondcompartment, wherein the transfer conduit comprises a collection headerconfigured to receive the crude oil stream from the first compartmentand provide fluid communication to the second compartment via thetransfer conduit; a horizontal electrical grid assembly disposed withinthe first compartment, the horizontal electrical grid assembly disposedbetween the collection header of the transfer conduit and at least oneof the plurality of distributors; a fluid mixer within the pressurevessel and is in fluid communication with the transfer conduit anddisposed between the collection header of the transfer conduit and adistributor of the transfer conduit disposed in the second compartment;a crude collector disposed within the second compartment, the crudecollector comprising a collection header configured to communicate fluidout of the second compartment to an outlet of the crude collector; and asecond horizontal electrical grid assembly disposed within the secondcompartment and aligned substantially transverse to a flow pathextending from the transfer conduit to the crude collection header.

A forty first embodiment can include the pressure vessel of the fortiethembodiment, wherein the horizontal electrical grid assembly is energizedby at least two alternating current (AC) power transformers.

A forty second embodiment can include the pressure vessel of thefortieth or forty first embodiment, wherein the horizontal electricalgrid assembly is configured to create a first voltage potential thatelectrostatically coalesces water from the crude oil stream intodroplets before the collection header of the transfer conduit.

A forty third embodiment can include the pressure vessel of any of thefortieth to forty second embodiments, wherein the horizontal electricalgrid assembly comprises at least three grid elements and a spacingadjuster configured to vary a distance between at least two of the gridelements.

A forty fourth embodiment can include the pressure vessel of any of thefortieth to forty third embodiments, wherein the fluid mixer comprisesat least one of a static mixer, an externally adjustable mixer, or acombination thereof.

A forty fifth embodiment can include the pressure vessel of any of thefortieth to forty fourth embodiments, wherein the second electrical gridassembly is disposed between the crude collection header and at least aportion of the transfer conduit.

A forty sixth embodiment can include the pressure vessel of any of thefortieth to forty fifth embodiments, wherein the second horizontalelectrical grid assembly is configured to create a second voltagepotential that electrostatically coalesces water into droplets beforethe crude collection header in the second compartment.

A forty seventh embodiment can include the pressure vessel of the fortysixth embodiment, wherein the second voltage potential created by thesecond horizontal electrical grid assembly is greater than the firstvoltage potential created by the first electrical grid assembly in thefirst compartment, wherein the second horizontal electrical gridassembly is energized by an AC power transformer.

While several embodiments have been provided in the present disclosure,it should be understood that the disclosed systems and methods may beembodied in many other specific forms without departing from the spiritor scope of the present disclosure. The present examples are to beconsidered as illustrative and not restrictive, and the intention is notto be limited to the details given herein. For example, the variouselements or components may be combined or integrated in another systemor certain features may be omitted or not implemented. The particularnaming of the components, capitalization of terms, the attributes,structures, or any other structural aspect is not mandatory orsignificant, and the mechanisms that implement the disclosure or itsfeatures may have different names, formats, or protocols. Also, theparticular division of functionality between the various componentsdescribed herein is merely exemplary, and not mandatory; functionsperformed by a single system component may instead be performed bymultiple components, and functions performed by multiple componentsinstead may be performed by a single component. Finally, it should benoted that the language used in the specification has been principallyselected for readability and instructional purposes, and may not havebeen selected to delineate or circumscribe the subject matter.

Also, techniques, systems, subsystems, and methods described andillustrated in the various embodiments as discrete or separate may becombined or integrated with other systems, modules, techniques, ormethods without departing from the scope of the present disclosure.Other items shown or discussed as directly coupled or communicating witheach other may be indirectly coupled or communicating through someinterface, device, or intermediate component, whether electrically,mechanically, or otherwise. Other examples of changes, substitutions,and alterations are ascertainable by one skilled in the art and could bemade without departing from the spirit and scope disclosed herein.

Where numerical ranges or limitations are expressly stated, such expressranges or limitations should be understood to include iterative rangesor limitations of like magnitude falling within the expressly statedranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4,etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example,whenever a numerical range with a lower limit, Rl, and an upper limit,Ru, is disclosed, any number falling within the range is specificallydisclosed. In particular, the following numbers within the range arespecifically disclosed: R=Rl+k*(Ru−Rl), wherein k is a variable rangingfrom 1 percent to 100 percent with a 1 percent increment, i.e., k is 1percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . 50 percent,51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98percent, 99 percent, or 100 percent. Moreover, any numerical rangedefined by two R numbers as defined in the above is also specificallydisclosed. Use of the term “optionally” with respect to any element of aclaim means that the element is required, or alternatively, the elementis not required, both alternatives being within the scope of the claim.The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any implementation described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other implementations. Use of broader terms such ascomprises, includes, and having should be understood to provide supportfor narrower terms such as consisting of, consisting essentially of, andcomprised substantially of. Accordingly, the scope of protection is notlimited by the description set out above but is defined by the claimsthat follow, that scope including all equivalents of the subject matterof the claims. Each and every claim is incorporated as furtherdisclosure into the specification and the claims are embodiment(s) ofthe present invention.

What is claimed is:
 1. A system for crude oil desalting and dehydration,the system comprising: a pressure vessel defining a cavity and extendingalong a central axis, the pressure vessel comprising: a sealed bulkheaddisposed within the cavity, the sealed bulkhead separating the cavityinto a first compartment and a second compartment; a first distributordisposed within the first compartment, wherein the first distributor isconfigured to receive a crude oil stream and provide fluid communicationinto the first compartment via an inlet of the first distributor; atransfer conduit that is disposed within the cavity, the secondcompartment being in fluid communication with the first compartment viathe transfer conduit; a first electrical grid assembly disposed withinthe first compartment, the first electrical grid assembly disposedbetween an intake of the transfer conduit and at least a portion of thefirst distributor; a crude outlet disposed within the secondcompartment, the crude outlet configured to communicate the crude oilout of the second compartment; a second electrical grid assemblydisposed within the second compartment, wherein the second electricalgrid assembly is not aligned with the first electrical grid assembly. 2.The system of claim 1, further comprising a fluid mixer, wherein thefluid mixer is in fluid communication with the transfer conduit anddisposed between an intake of the transfer conduit and a distributor ofthe transfer conduit, wherein the fluid mixer comprises a static mixeror an externally adjustable mixer.
 3. The system of claim 1, wherein thefirst electrical grid assembly is configured to be energized by a powertransformer, and wherein the first electrical grid assembly isconfigured to create a first voltage potential that electrostaticallycoalesces water from the crude oil stream into droplets before theintake of the transfer conduit.
 4. The system of claim 1, wherein thefirst electrical grid assembly comprises at least two grid elements anda spacing adjuster configured to vary a distance between at least two ofthe grid elements.
 5. The system of claim 1, wherein the pressure vesselfurther comprising an overflow weir disposed within the firstcompartment, wherein the overflow weir is configured to define a passageover the weir that directs the crude oil stream toward the intake of thetransfer conduit and mitigate coalesced droplets from entering theintake of the transfer conduit.
 6. The system of claim 1, wherein thesecond electrical grid assembly is disposed between the crude outlet andat least a portion of the transfer conduit, and wherein the secondelectrical grid assembly comprises at least two grid elements that eachextend substantially orthogonal to the first electrical grid assembly.7. A method of desalting and dehydrating crude oil via a single pressurevessel, the method comprising: receiving a crude oil stream into a firstdistributor disposed within a first compartment of a pressure vessel,the first compartment being separated from a second compartment by asealed bulkhead, the first compartment comprising a first electricalgrid assembly; injecting, within the first compartment via the firstdistributor, the crude oil stream before at least a portion of the firstelectrical grid assembly along a first flow path; electrostaticallycoalescing, by passing the diluted crude oil stream through the firstelectrical grid assembly being energized to a first voltage potential,water from the crude oil stream into droplets; preventing, within thefirst compartment, coalesced droplets from entering an intake of atransfer conduit by separating the coalesced droplets from the intake ofthe transfer conduit, wherein the transfer conduit is within thepressure vessel and passes through the sealed bulkhead and fluidlycommunicates the crude oil stream from the first compartment to thesecond compartment; transferring the crude oil stream to the secondcompartment via the transfer conduit; diluting, via a dilution conduitand a fluid mixer inline with the transfer conduit, the crude oil streamin the transfer conduit with a diluent; subsequent to diluting,distributing, via a distributor of the transfer conduit in the secondcompartment, the diluted crude oil stream before at least a portion of asecond electrical grid assembly; electrostatically coalescing, bypassing the diluted crude oil stream through the second electrical gridassembly being energized to a second voltage potential, water from thediluted crude oil stream into droplets; subsequent to theelectrostatically coalescing, removing crude oil from the secondcompartment via a crude collector disposed within the secondcompartment.
 8. The method of claim 7, wherein preventing coalesceddroplets from entering the intake of the transfer conduit is based on anoverflow weir separating the coalesced droplets from the intake of thetransfer conduit, and wherein preventing coalesced droplets fromentering the intake of the transfer conduit is based on the intake ofthe transfer conduit being disposed within the first compartment at anelevation at or above the first electrical grid assembly.
 9. The methodof claim 7, further comprising removing the coalesced droplets from thefirst compartment via an outlet in the vessel.
 10. The method of claim7, wherein diluting comprises introducing the diluent into the transferconduit via the dilution conduit and mixing the crude oil stream withthe diluent via the fluid mixer, and wherein introducing the diluentoccurs upstream from the fluid mixer.
 11. The method of claim 7, whereinthe second electrical grid assembly comprises at least two grid elementsthat each extend substantially orthogonal to the first electrical gridassembly.
 12. The system of claim 1: wherein the transfer conduit passesthrough the sealed bulkhead from the first compartment to the secondcompartment, wherein the transfer conduit comprises a collection headerconfigured to receive the crude oil stream from the first compartmentand provide fluid communication to the second compartment via thetransfer conduit; wherein the first electrical grid assembly comprises ahorizontal electrical grid assembly disposed within the firstcompartment, the horizontal electrical grid assembly disposed betweenthe collection header of the transfer conduit and at least a portion ofthe first distributor; and wherein the second grid assembly comprises avertical electrical grid assembly disposed within the second compartmentand aligned substantially transverse to a horizontal flow path extendingfrom the transfer conduit to an overflow weir, wherein the verticalelectrical grid assembly is energized by a direct current (DC) powertransformer.
 13. The system of claim 12, wherein the horizontalelectrical grid assembly is energized by an alternating current (AC)power transformer.
 14. The system of claim 12, wherein the verticalelectrical grid assembly is configured to create a second voltagepotential that electrostatically coalesces water into droplets beforethe overflow weir, and wherein the second voltage potential created bythe vertical electrical grid assembly is greater than a first voltagepotential created by the horizontal electrical grid assembly.
 15. Thesystem of claim 12, wherein the pressure vessel further comprising adilution conduit that defines a channel extending from outside thecavity and into the transfer conduit, wherein a fluid mixer is in fluidcommunication with the transfer conduit and disposed between an intakeof the transfer conduit and a distributor of the transfer conduit, andwherein the dilution conduit is configure to introduce dilution fluidwithin the transfer conduit and upstream of the fluid mixer.
 16. Thesystem of claim 15, wherein the dilution fluid comprises at least one ofwater, a demulsifier, or a combination thereof.
 17. The system of claim12, wherein the vertical electrical grid assembly is disposed betweenthe overflow weir and at least a portion of the transfer conduit.
 18. Apressure vessel for crude oil desalting and dehydration, the pressurevessel comprising: a sealed bulkhead disposed within a cavity defined bythe pressure vessel, the sealed bulkhead configured to divide the cavityinto a first compartment and a second compartment; a plurality ofdistributors disposed within the first compartment, wherein each of theplurality of distributors is configured to receive a crude oil streamand provide fluid communication into the first compartment via inlets; atransfer conduit that is disposed within the cavity and passes throughthe bulkhead from the first compartment to the second compartment,wherein the transfer conduit comprises a collection header configured toreceive the crude oil stream from the first compartment and providefluid communication to the second compartment via the transfer conduit;a horizontal electrical grid assembly disposed within the firstcompartment, the horizontal electrical grid assembly disposed betweenthe collection header of the transfer conduit and at least one of theplurality of distributors; a fluid mixer within the pressure vessel andis in fluid communication with the transfer conduit and disposed betweenthe collection header of the transfer conduit and a distributor of thetransfer conduit disposed in the second compartment; a crude collectordisposed within the second compartment, the crude collector comprising acollection header configured to communicate fluid out of the secondcompartment to an outlet of the crude collector; and a second horizontalelectrical grid assembly disposed within the second compartment andaligned substantially transverse to a flow path extending from thetransfer conduit to the crude collection header.
 19. The pressure vesselof claim 18, wherein the horizontal electrical grid assembly isenergized by at least two alternating current (AC) power transformers,and wherein the horizontal electrical grid assembly comprises at leastthree grid elements and a spacing adjuster configured to vary a distancebetween at least two of the grid elements.
 20. The pressure vessel ofclaim 18, wherein the second horizontal electrical grid assembly isconfigured to create a second voltage potential that electrostaticallycoalesces water into droplets before the crude collection header in thesecond compartment, and wherein the second voltage potential created bythe second horizontal electrical grid assembly is greater than the firstvoltage potential created by the first electrical grid assembly in thefirst compartment.